We notice that our Rocky server 9.6 issues the following errors the last few weeks and also we notice that our nfs clients (Rocky 9.x and 10.x) freezing for few seconds while users are using their home directory which is on the nfs mount.
\[Wed Jun 10 18:30:26 2026\] INFO: task kworker/u96:3:132223 blocked for more than 122 seconds.
\[Wed Jun 10 18:30:26 2026\] Tainted: G S ------ --- 5.14.0-687.12.1.el9_8.x86_64 #1
\[Wed Jun 10 18:30:26 2026\] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
\[Wed Jun 10 18:30:26 2026\] task:kworker/u96:3 state:D stack:0 pid:132223 tgid:132223 ppid:2 flags:0x00004000
\[Wed Jun 10 18:30:26 2026\] Workqueue: nfsd4 laundromat_main \[nfsd\]
\[Wed Jun 10 18:30:26 2026\] Call Trace:
\[Wed Jun 10 18:30:26 2026\]
\[Wed Jun 10 18:30:26 2026\] \__schedule+0x22c/0x540
\[Wed Jun 10 18:30:26 2026\] schedule+0x2c/0xb0
\[Wed Jun 10 18:30:26 2026\] nfsd4_shutdown_callback+0xa3/0x120 \[nfsd\]
\[Wed Jun 10 18:30:26 2026\] ? \__pfx_var_wake_function+0x10/0x10
\[Wed Jun 10 18:30:26 2026\] \__destroy_client+0x1f0/0x290 \[nfsd\]
\[Wed Jun 10 18:30:26 2026\] nfs4_process_client_reaplist+0xa1/0x110 \[nfsd\]
\[Wed Jun 10 18:30:26 2026\] nfs4_laundromat+0x126/0x7a0 \[nfsd\]
\[Wed Jun 10 18:30:26 2026\] laundromat_main+0x16/0x40 \[nfsd\]
\[Wed Jun 10 18:30:26 2026\] process_one_work+0x188/0x3b0
\[Wed Jun 10 18:30:26 2026\] worker_thread+0x2ef/0x410
\[Wed Jun 10 18:30:26 2026\] ? \__pfx_worker_thread+0x10/0x10
\[Wed Jun 10 18:30:26 2026\] kthread+0x122/0x240
\[Wed Jun 10 18:30:26 2026\] ? \__pfx_kthread+0x10/0x10
\[Wed Jun 10 18:30:26 2026\] ? \__pfx_kthread+0x10/0x10
\[Wed Jun 10 18:30:26 2026\] ret_from_fork+0x28/0x50
\[Wed Jun 10 18:30:26 2026\]
We also note that the errors seems to be the delegation communication between the clients.
Running the command cat /proc/fs/nfsd/clients/*/info
we get among others
clientid: 0x5474792f6a2680bb
address: "10.16.9.100:679"
status: courtesy
seconds from last renew: 261553
name: "Linux NFSv4.2 101ws31.xx.yy"
minor version: 2
Implementation domain: "kernel.org"
Implementation name: "Linux 5.14.0-611.55.1.el9_7.0.3.x86_64 #1 SMP PREEMPT_DYNAMIC Mon May 18 19:21:10 UTC 2026 x86_64"
Implementation time: \[0, 0\]
callback state: UNKNOWN
callback address: 10.16.9.100:0
admin-revoked states: 0
clientid: 0x547479336a2680bb
address: "10.16.9.100:733"
status: confirmed
seconds from last renew: 261553
name: "Linux NFSv4.2 101ws31.xx.yy"
minor version: 2
Implementation domain: "kernel.org"
Implementation name: "Linux 5.14.0-611.55.1.el9_7.0.3.x86_64 #1 SMP PREEMPT_DYNAMIC Mon May 18 19:21:10 UTC 2026 x86_64"
Implementation time: \[0, 0\]
callback state: DOWN
callback address: 10.16.9.100:0
admin-revoked states: 0
Also yesterday we upgrade to ver 9.8 and we notice that the command nfsdclnts --hostname gives the errors below instead of the output
Inode number | Type | Access | Deny | Hostname | Filename
Traceback (most recent call last):
File “/usr/sbin/nfsdclnts”, line 255, in
nfsd4_show()
File “/usr/sbin/nfsdclnts”, line 247, in nfsd4_show
printer(item, args)
File “/usr/sbin/nfsdclnts”, line 90, in printer
inode = i[key][‘superblock’].split(‘:’)[-1]
KeyError: ‘superblock’
Any suggestions please that may help?
Best regards
Maria